Human Anatomy-and-Physiology - JP UK notes by Nelson PDF

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ANATOMY AND PHYSIOLOGY UNIT-I

INTRODUCTION TO ANATOMICAL TERMS

٠ Anatomy and physiology are branches of biology. The human body is a very complex multi cellar organism in which the maintenance of life cycle depends upon a most number of physiological activities. •

Definition: ٠ Anatomy: is the study of the structure and architecture of the body and of the relationship of its surrounding structure. ٠ Process of cutting the human body to understand anatomy is Dissection. ٠ Physiology deals with functions of the body it explains the working of different body parts in supporting life. ٠ Anatomy is subdivided into specific areas of study. They are, 1. Gross Anatomy: It is the study of body parts visible to naked eye. 2. Cytology: It is the study of individual cell microscope. 3. Histology: It is the study of microscopic structures of tissues. 4. Embryology: It is the study of developing embryo. 5. Osteology: It is the study of the bones. 6. Arthrology: It is the study of the joints. 7. Myology: It is the study of the muscular system. 8. Neurology: It is the study of the brain and nerves.

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Positions: •

Anatomical position: The subject stands erect facing the examiner, eye facing forwards, feet flat on the floor directed forwards and arms by side with the palms facing forwards.

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Prone position: In this the subject is lying with face down.

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Supine position: In this the subject is lying with face up.

Body planes: •

Sagittal plane: It is the vertical plane that divides the body or an organ into right and left sides.

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Coronal plane: It divides the body into anterior (front) and posterior (back) portions.

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Transverse plane: It divides the body into superior (upper) and inferior (lower) portions.

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Oblique plane: It passes through the body at an angle between transverse, Sagittal plane.

Terms used to describe the body parts: •

Medial: Is nearer to midline or median plane. 1

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Lateral: Is away from midline or median plane.

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Anterior/Ventral: Is nearer to front of the body.

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Posterior/Dorsal: Is closer to back of the body.

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Superior: Is towards the head or upper part of the structure that is studied.

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Inferior: Is away from the head or lower part of the structure.

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Superficial: Is towards or on the surface of the body.

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Deep: Is away from the surface of the body.

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Proximal: Is nearer to the point of origin or nearer to attachment of limb to the trunk.

Terms used to movement: •

Joint: Is a site where two or more bones come together. Movements are take place in the body at joints.

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Flexion: Is a movement in the Sagittal plane, anterior surface of the forearm moves towards anterior surface of arm. There is a decrease in angle between the articulating bones.

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Extension: Is a movement in the posterior direction, an increase in angle between the articulating bones.

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Abduction: Is the movement of limb away from midline of the body in coronal plane.

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Adduction: Is the movement of limb towards the body in coronal plane.

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Rotation: Is the movement of body parts around its own long axis.

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Medial rotation: Is the movement in which anterior surface of the part moves medially.

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Lateral rotation: Is the movement in which anterior surface of the part moves laterally.

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Pronation: The forearm is medial rotation of the forearm, palm faces posteriorly.

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Supination: The forearm is lateral rotation of the forearm, palm faces interiorly.

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Opposition: the movement of thumb across the palm to touch fingertips.

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Circumduction: The movement of distal part of the body in a circle.

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Elevation: An upward movement of a part of the body.

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Inversion: The movement of foot where sole of the foot turns medially.

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Eversion: The movement of foot where sole of the foot turns laterally.

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Abnormal movements: Dislocation means the displacement of bone from its joint.

Terms used in disease: •

Pathology: It is the study of diseases.

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Etiology: It is the study of factors involved in the causes of disease.

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Pathogenesis: It is the pattern of development of the disease.

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Epidemiology: It is the study of occurrence, distribution and transmission of a disease.

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Diagnosis: It is the process of identifying the disease based on signs and symptoms.

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Signs: Abnormalities produced by a disease that can be seen or measured.

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Symptoms: Subjective abnormalities complained by the patient. 2

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Acute disease: A condition in which the sign and symptoms appear suddenly, remain for a short duration and disappear.

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Chronic disease: Those that develop slowly, remain for a long time.

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Idiopathic disease: They are those where the cause is not established.

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Communicable disease: They are those that spread from one person to another.

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Endemic disease: Those occur in a localized region.

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Epidemic: Is the spread of disease to a number of individuals at the same time.

Body Functions Body functions are the physiological or psychological functions of body systems. The body's functions are ultimately its cells' functions. Survival is the body's most important business. Survival depends on the body's maintaining or restoring homeostasis, a state of relative constancy, of its internal environment. More than a century ago, French physiologist, Claude Bernard (1813-1878), made a remarkable observation. He noted that body cells survived in a healthy condition only when the temperature, pressure, and chemical composition of their environment remained relatively constant. Later, an American physiologist, Walter B. Cannon (1871-1945), suggested the name homeostasis for the relatively constant states maintained by the body. Homeostasis is a key word in modern physiology. It comes from two Greek words - "homeo," meaning the same, and "stasis," meaning standing. "Standing or staying the same" then is the literal meaning of homeostasis. However, as Cannon emphasized, homeostasis does not mean something set and immobile that stays exactly the same all the time. In his words, homeostasis "means a condition that may vary, but which is relatively constant." Homeostasis depends on the body's ceaselessly carrying on many activities. Its major activities or functions are responding to changes in the body's environment, exchanging materials between the environment and cells, metabolizing foods, and integrating all of the body's diverse activities. The body's ability to perform many of its functions changes gradually over the years. In general, the body performs its functions least well at both ends of life - in infancy and in old age. During childhood, body functions gradually become more and more efficient and effective. During late maturity and old age the opposite is true. They gradually become less and less efficient and effective. During young adulthood, they normally operate with maximum efficiency and effectiveness. Life Process All living organisms have certain characteristics that distinguish them from non-living forms. The basic processes of life include organization, metabolism, responsiveness, movements, and reproduction. In humans, who represent the most complex form of life, there are additional requirements such as growth, differentiation, respiration, digestion, and excretion. All of these processes are interrelated. No part of the body, from the smallest cell to a complete body system, works in isolation. All function together, in fine-tuned balance, for the well being of the individual and to maintain life. Disease such as cancer and death represent a disruption of the balance in these processes.

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The following are a brief description of the life process: Organization At all levels of the organizational scheme, there is a division of labor. Each component has its own job to perform in cooperation with others. Even a single cell, if it loses its integrity or organization, will die. Metabolism Metabolism is a broad term that includes all the chemical reactions that occur in the body. One phase of metabolism is catabolism in which complex substances are broken down into simpler building blocks and energy is released. Responsiveness Responsiveness or irritability is concerned with detecting changes in the internal or external environments and reacting to that change. It is the act of sensing a stimulus and responding to it. Movement There are many types of movement within the body. On the cellular level, molecules move from one place to another. Blood moves from one part of the body to another. The diaphragm moves with every breath. The ability of muscle fibers to shorten and thus to produce movement is called contractility. Reproduction For most people, reproduction refers to the formation of a new person, the birth of a baby. In this way, life is transmitted from one generation to the next through reproduction of the organism. In a broader sense, reproduction also refers to the formation of new cells for the replacement and repair of old cells as well as for growth. This is cellular reproduction. Both are essential to the survival of the human race. Growth Growth refers to an increase in size either through an increase in the number of cells or through an increase in the size of each individual cell. In order for growth to occur, anabolic processes must occur at a faster rate than catabolic processes. Differentiation Differentiation is a developmental process by which unspecialized cells change into specialized cells with distinctive structural and functional characteristics. Through differentiation, cells develop into tissues and organs. Respiration Respiration refers to all the processes involved in the exchange of oxygen and carbon dioxide between the cells and the external environment. It includes ventilation, the diffusion of oxygen and carbon dioxide, and the transport of the gases in the blood. Cellular respiration deals with the cell's utilization of oxygen and release of carbon dioxide in its metabolism. Digestion 4

Digestion is the process of breaking down complex ingested foods into simple molecules that can be absorbed into the blood and utilized by the body. Excretion Excretion is the process that removes the waste products of digestion and metabolism from the body. It gets rid of by-products that the body is unable to use, many of which are toxic and incompatible with life. The ten life processes described above are not enough to ensure the survival of the individual. In addition to these processes, life depends on certain physical factors from the environment. These include water, oxygen, nutrients, heat, and pressure. MORE ANATOMICAL TERMINOLOGIES Three groups of terms are introduced here: •

Directional Terms

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Planes of the Body Body Cavities

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Directional Terms Directional terms describe the positions of structures relative to other structures or locations in the body. Superior or cranial - toward the head end of the body; upper (example, the hand is part of the superior extremity). Inferior or caudal - away from the head; lower (example, the foot is part of the inferior extremity). Anterior or ventral - front (example, the kneecap is located on the anterior side of the leg). Posterior or dorsal - back (example, the shoulder blades are located on the posterior side of the body). Medial - toward the midline of the body (example, the middle toe is located at the medial side of the foot). Lateral - away from the midline of the body (example, the little toe is located at the lateral side of the foot). Proximal - toward or nearest the trunk or the point of origin of a part (example, the proximal end of the femur joins with the pelvic bone). Distal - away from or farthest from the trunk or the point or origin of a part (example, the hand is located at the distal end of the forearm).

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Planes of the Body

Coronal Plane (Frontal Plane) - A vertical plane running from side to side; divides the body or any of its parts into anterior and posterior portions. Sagittal Plane (Lateral Plane) - A vertical plane running from front to back; divides the body or any of its parts into right and left sides. Axial Plane (Transverse Plane) - A horizontal plane; divides the body or any of its parts into upper and lower parts. Median plane - Sagittal plane through the midline of the body; divides the body or any of its parts into right and left halves. Body Cavities The cavities, or spaces, of the body contain the internal organs, or viscera. The two main cavities are called the ventral and dorsal cavities. The ventral is the larger cavity and is subdivided into two parts (thoracic and abdominopelvic cavities) by the diaphragm, a dome-shaped respiratory muscle.

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Thoracic cavity The upper ventral, thoracic, or chest cavity contains the heart, lungs, trachea, esophagus, large blood vessels, and nerves. The thoracic cavity is bound laterally by the ribs (covered by costal pleura) and the diaphragm caudally (covered by diaphragmatic pleura). Abdominal and pelvic cavity The lower part of the ventral (abdominopelvic) cavity can be further divided into two portions: abdominal portion and pelvic portion. The abdominal cavity contains most of the gastrointestinal tract as well as the kidneys and adrenal glands. The abdominal cavity is bound cranially by the diaphragm, laterally by the body wall, and caudally by the pelvic cavity. The pelvic cavity contains most of the urogenital system as well as the rectum. The pelvic cavity is bounded cranially by the abdominal cavity, dorsally by the sacrum, and laterally by the pelvis. Dorsal cavity The smaller of the two main cavities is called the dorsal cavity. As its name implies, it contains organs lying more posterior in the body. The dorsal cavity, again, can be divided into two portions. The upper portion, or the cranial cavity, houses the brain, and the lower portion, or vertebral canal houses the spinal cord.

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UNIT-II

HUMAN CELL STRUCTURE & FUNCTIONS

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In human each and every function is performed by specific system of the body.

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Each organ system is made up of various tissues. Each tissue is made up of millions and millions of small units, termed Cells.

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Cell contains, ◦ Water: 70- 75% of the cell is made up of water. ◦ Electrolytes: major electrolytes include potassium, magnesium, sodium, phosphate, sulphate, bicarbonate, chloride and calcium. ◦ Proteins: They constitute 10-20% of the cell mass. They are of types; Globular and Structural Proteins. ◦ Lipids: They constitute 2% of cell mass. They are made up of phospholipids and cholesterol. ◦ Carbohydrates: They form around 1% of cell mass. They play a major role in providing nutrition to the cell.

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Structure of Cell: Cell is made up of two major parts; Nucleus & Cytoplasm

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Cytoplasm is the fluid part of cell containing the organelles. It is covered by an envelope termed as Cell membrane.

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Cell membrane: It is the membrane surrounding the cell. It covers the nucleus and the cytoplasm. It is a semi permeable membrane. It is 7-10 mm thick. The membrane is made up of proteins, lipids, and a little of carbohydrates. It is made up of two layers of phospholipids. 1. Function of lipids: They foam the cell membrane. They allow fat soluble substances to pass through them easily. 2. Function of proteins: They act as structural proteins, form ion channels, act as receptors and enzymes. 3. Function of carbohydrates: They act as receptors for binding hormones, and participate in immune reactions.

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Nucleus: It is a spherical shape structure covered by a nuclear membrane. It is controls chemical reactions and reproduction of the cell. Nucleus is mainly made up of water, 80% of the dry weight is proteins, 18% DNA and 2% RNA. It contains densely staining network of DNA and protein, is called Chromatin. Genes are the units of heredity. Each gene is a portion of DNA molecule. They are present on the chromosome. Human beings have 23 pairs of chromosomes. 1. Nuclear membrane: It has two layers, the outer and the inner layer. The outer layer is continuous with endoplasmic reticulum.

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2. Nucleoli: These are lightly stained structures in the nucleus. Nucleoli synthesize and store RNA and proteins, which play an important role in protein synthesis. •

Cytoplasm: It contains a fluid portion of the cell in which organelles are present. The fluid portion is called Cytosol. It contains dissolved proteins, glucose and electrolytes. It contains the following cellular organelles. ٠ Mitochondria: It is the also called Power house of the cell. It is a sausage shaped structure made up of an outer membrane and an inner membrane. Inner membrane is folded to form shelves called Cristae, filled with Matrix containing dissolved enzymes. ٠ Ribosomes: They are present on the outer surface of endoplasmic reticulum. They are also present freely in the cytoplasm; Ribosomes are made up of RNA and proteins. ٠ Endoplasmic reticulum:

This is a network of tubular and flat vesicular structure

interconnected with each other, space between the tubules and vesicles are filled with watery fluid termed Endoplasmic matrix. This is of two types; -

Rough E.R: Granular (Ribosome’s) structure on it surface helps in synthesis of proteins.

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Smooth E.R: Does not have Ribosomes on its surface helps in synthesis of lipids, glycogen metabolism.

٠ Golgi apparatus: This same like smooth endoplasmic reticulum. It is made of

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layers of thin flat vesicles lying near the nucleus. Its helps in the synthesis of carbohydrate. 9

٠ Lysosomes: They are formed by Golgi apparatus and are present throughout the cytoplasm. Function is removal of unwanted, damaged substances and foreign bodies like bacteria. ٠ Centrosomes: They are structures present near the nucleus. They are made up of structures called Centrioles. It plays an important part during the steps of cell division. ٠ Microtubules: These are long hollow structures and are formed by organization of microfilament into tubular structures. It helps to transportation of organelles like mitochondria from one part of cell to another. •

Cell division: There are two type of cell division; Mitosis and Meiosis.

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Mitosis: Cell division begins with fertilized egg or single cell zygote. In this replication of DNA in form of 23 pairs of chromosomes and the division of the cytoplasm. This has four phases; 1. Prophase: In this phase Centrioles move apart and form poles of mitotic spindle. Each chromosome is made of a pair of chromatids attached to the centromere. 2.

Metaphase: Chromosomes move to equator of the spindle. Chromosomes split and chromatids get separated, Centrioles duplicate resulting in two Centrioles at each pole of the spindle.

3. Anaphase: Separated chromatids move towards opposite p...